Cell biology and proposed mechanisms
Glutathione
Glutathione is a small molecule made of three amino acids that every human cell manufactures for itself. It is the body's most abundant internal antioxidant, neutralising peroxides and reactive chemicals, and it is recycled between a reduced form (GSH) and an oxidised form (GSSG).
Also called GSH, reduced glutathione, GSSG, glutathione peroxidase
What it is
Glutathione is a tripeptide of glutamate, cysteine and glycine. Cells make it in two enzyme steps; they do not import it intact from food in any significant quantity. Concentrations inside a cell are in the millimolar range, far higher than any vitamin. Glutathione: overview of its protective roles, measurement, and biosynthesis, Molecular Aspects of Medicine (2009), is a standard reference.
Its jobs are to reduce hydrogen peroxide and lipid peroxides via the enzyme glutathione peroxidase, to conjugate and so neutralise foreign electrophilic chemicals, and to keep protein cysteines in the right redox state. The ratio of reduced (GSH) to oxidised (GSSG) glutathione is one of the most-used laboratory measures of a cell’s redox state.
Where it appears in ozone therapy
Glutathione is one of the molecules downstream of Nrf2, so it sits at the end of the proposed oxidative preconditioning chain. Bocci names free reduced glutathione, alongside catalase and glutathione peroxidase, as the reason a rise in hydrogen peroxide inside a red blood cell is not toxic. In the rat study Ozone oxidative preconditioning: a protection against cellular damage by free radicals, Mediators of Inflammation (1998), reduced glutathione was one of the parameters measured.
One thing worth knowing
Glutathione status is measurable in blood or tissue, which makes it one of the more checkable things in this vocabulary. Oral glutathione supplements are largely broken down in the gut, which is a separate and much-debated topic.
Why it matters here
Glutathione is one of the few things in this vocabulary that shows up in an ordinary laboratory test. It is the body's own antioxidant, made inside your cells rather than swallowed.